Mr Davis said Mr Brown had landed private firms and their employees with a pensions "double whammy".

He said Mr Brown had raided pensions funds and imposed other stealth taxes on private firms while ducking reform of public sector pensions.

"The effect of this crisis go well beyond the economy," he said.

"I believe Mr Brown's assault on pensions has seriously eroded the cultures of thrift and self-reliance which are the cornerstones of any successful economy."

It now paid not to save, said Mr Davis.

Mr Davis said he expected to be able to give £38bn in tax cuts by the end of his first term in government by ensuring spending on public services rises more slowly than overall growth in the economy.

Risk culture

In his speech, Mr Cameron said it was too early to unveil specific tax proposals - instead he said he wanted to share the proceeds of economic growth between tax cuts and investment in public services.

Governments could not create wealth or run businesses but they could set the right conditions, he said.

Mr Cameron set out five barriers to growth: irresponsible government borrowing; the burden of regulations; European social and employment laws; problems with infrastructure, such as transport networks; and education failures.

He said the consequence of the decline in support for capitalism was a risk averse culture where people wanted the state to try to protect them against risk.

Mr Cameron said his approach was based on economic liberalism, with the watchwords of "trusting people and sharing responsibility".

Surprise ahead?

Earlier, Mr Davis insisted he could still be a surprise winner of the Tory leadership contest.

Opinion polls suggest Mr Cameron is set to win the contest, whose result is due to be announced on 6 December.

But Mr Davis told BBC Radio 4's Today programme the leader was being chosen by the wider Tory membership, rather than internet polls, adding: "You may be surprised."